Port StackExtensionsTests to UnitTests.Parallelizable

Co-authored-by: tig <[email protected]>

Tests/UnitTests/Application/StackExtensionsTests.cs → Tests/UnitTestsParallelizable/Application/StackExtensionsTests.cs

@@ -1,6 +1,6 @@
-namespace Terminal.Gui.ApplicationTests;
+namespace Terminal.Gui.ApplicationTests;
 
-public class StackExtensionsTests
+public class StackExtensionsTests : UnitTests.Parallelizable.ParallelizableBase
 {
     [Fact]
     public void Stack_Toplevels_Contains ()